McConnell led with 62 percent to 33 percent for Louisville businessman Matt Bevin when The Associated Press called the race with just 7 percent of precincts reporting.

The primary served as the formal kickoff to what's expected to be a highly competitive general-election race with Democrat Alison Lundergan Grimes, Kentucky's secretary of State, who also won her primary by a wide margin. In one of Democrats' two pickup opportunities in 2014, recent polls have found the race neck-and-neck. But before the race could officially kick off, McConnell had to dispense with his most dangerous primary challenge to date. The minority leader had already spent $11.6 million by April 30, but he still had more than $10 million on hand.

Bevin was backed by anti-establishment groups like Senate Conservatives Fund, but the amount of money spent on the airwaves in support of Bevin was dwarfed by McConnell and his allies . The first-time candidate also faced bizarre questions about inflating his resume and ties to a cock-fighting ring that did not help his chances.

In Grimes, McConnell will face a well-funded and so far disciplined challenger who is running as an independent voice for Kentucky. The campaign to tie her to President Barack Obama and national Democrats is well underway, including a pro-McConnell super PAC ad hitting the airwaves Wednesday.

At the same time, McConnell will be working to unify the GOP after a significant percentage of the primary electorate voted to send him home. That process started Tuesday night, as SCF and other groups working against him urged supporters to back the minority leader, who hopes to lead a majority if Republicans win a net six seats in November.

"Make me the majority leader, and Kentucky will lead America," McConnell told the crowd assembled at his election night victory party.

In her nomination acceptance speech, Grimes pushed back on McConnell tying her to the president and said the longtime senator has lost touch with the state.

"President Obama is not on Kentucky’s 2014 election ballot," Grimes told the assembled crowd. "Nothing about this election can change who is in the White House, but it can change who is in Washington" representing Kentucky.